PLAYIN' THE FIELD: Carlos Beltran will make his right field debut today in an intra-squad scrimmage with minor leaguers. N.Y. Post: Photo: Charles Wenzelberg

JUPITER, Fla. — It took a month of spring training games, but the Mets’ new right fielder finally will get to play right field.

Granted, Carlos Beltran’s debut in right will occur in an intra-squad scrimmage against minor leaguers. But for the Mets, today’s Beltran appearance in right field represents the best hope yet his gimpy left knee is ready for opening night.

If Beltran passes this test, manager Terry Collins can start seriously considering the lineup in his desk drawer for Friday’s opener against the Marlins — which shows Beltran batting cleanup — as a safe bet.

“Even though he is feeling great, it’s a big step forward for us to get him out there and get him playing,” Collins said after the Mets lost 6-5 to the Marlins yesterday. “We’re going to watch it. That is why I just said, ‘Get some at-bats while you’re at it and run the bases a little bit so we get a complete take on how you’re going to feel when you get out of it.’ ”

Today’s plan calls for Beltran to play five innings in right. He also will bat five times — as the leadoff hitter in each inning.

Yesterday, Beltran was the designated hitter in a minor league scrimmage that included Chris Young and Jason Isringhausen. Beltran finished 5-for-10 and jogged around the bases to give his knee a rest. But the Mets saw plenty the previous day, when Beltran participated in a simulated game and ran full steam on the bases.

“Based on everything I did [Thursday], I feel confident that everything is going to be fine,” said Beltran, who is recovering from tendinitis in his left knee. “I haven’t been able to be on the field and play in games, but I’ve been able to do a lot of things hitting wise to put myself in condition so when I start playing games I’m not too far behind.”

Beltran is expected to get a day off tomorrow and could be inserted into the Mets’ lineup as the right fielder for Monday’s exhibition game against the Marlins. Collins said it’s still too early for the Mets to be too excited about potentially having Beltran for the opener.

“Everybody is looking forward to having him in the lineup, but I do believe they also have been thinking in their minds, ‘If he’s not there, somebody else is going to have to pick it up,’ ” Collins said. “We’ll just adjust the lineup, but I know one thing: Our guys are ready to move forward and get this thing started, for sure.”

Beltran said he is just glad his rehab has shifted to the baseball field after two weeks of taking it cautiously.

“Sometimes you train hard in the weight room and do a lot of cardio and things, but when you run on the field it’s a different story,” Beltran said. “You can never prepare yourself off the field for what you do in the field running the bases.”